Judging by posts and comments by graduate students in math.stackexchange.com and mathoverflow.net, I have come to the conclusion that a large part of their knowledge comes from SE sites and the Wikipedia, as opposed to traditional publications such as books and papers.
I was deeply shocked the first time I heard of a student researching the literature through Google, which spits out at least as many SE and Wikipedia answers as references to books and journals. But, of course, nowadays I do the same, certainly more often than going to the library!
(Edited below:)
Are traditional publication forms becoming obsolete, in the face of purely electronic forms? Or, contrariwise, do younger people who ignore traditional forms miss out on essential information?